In general, when a process of manufacturing a semiconductor chip such as an integrated circuit (IC) or the like is ended, an electric performance, a poor quality, etc., of the semiconductor chip are tested. When the semiconductor chip is tested, a test socket is provided between a test device and the semiconductor chip to electrically connect lead terminals of the semiconductor chip to test terminals of the test device. A current flows from the test terminals of the test device into the lead terminals of the semiconductor chip through the test socket, and signals respectively output from the lead terminals are analyzed to determine whether the semiconductor chip is abnormal.
As shown in FIG. 1, a conventional test socket is installed on a test device 20 and includes pogo pins 50 and a housing 30 that supports the pogo pins 50.
The housing 30 has through-holes formed in positions corresponding to test terminals 22 of the test device 20 and lead terminals 12 of a semiconductor chip 10, and the pogo pins 50 are respectively installed in the through-holes to electrically connect the lead terminals 12 to the test terminals 22.
The pogo pins 50 include barrels 52, upper plungers 54, lower plungers 56, and springs 58. The upper and lower plungers 54 and 56 are respectively connected to the lead terminals 12 of the semiconductor chip 10 and the test terminals 22 of the test device 20. The springs 58 are disposed between the upper and lower plungers 54 and 56 and provide elasticity and electric conductivity. The barrels 52 support and enclose the upper and lower plungers 54 and 56 and the springs 58.
The pogo pins 50 have serial structures of the upper plungers 54, the barrels 52, and the lower plungers 56. Since the pogo pins 50 also include the springs 58, manufacturing heights of the pogo pins 50 are greatly limited. Also, since the pogo pins 50 have wide areas as a whole, mutual inductance and capacitance between the adjacent pogo pins 50 increase. As a result, lengths and magnetic inductance values of the pogo pins 50 increase due to the springs 58, thereby deteriorating signal (electricity) transmission characteristics.
A semiconductor chip which includes lead terminals having narrow distances from one another and thus has a fine pitch has been developed. Therefore, a pitch of a test socket is also narrowed. However, it is not easy to reduce distances between barrels of conventional pogo pins and to form metal plating layers in the barrels.
Also, manufacturing cost of a test socket is very high due to micromachining of the upper and lower plungers 54 and 56 and the barrels 52 of the pogo pins 50.
In order to solve these problems, a technique for using a single spring in a test socket, as shown in FIG. 2, has been applied. In other words, the test socket is mounted on a test device 20 and includes spring pins 70 having spring shapes and a housing 30 that supports the spring pins 70.
Through-holes 60 are respectively formed in positions of the housing 30 corresponding to test terminals 22 of the test device 20 and lead terminals 12 of a semiconductor chip 10. The spring pins 70 are respectively installed in the through-holes 60 to electrically connect the lead terminals 12 to the test terminals 22.
A metal steel wire is coiled in a spiral to form the spring pins 70. Manufacturing cost of the spring pins 70 is less than that of the pogo pins 50 illustrated with reference to FIG. 1. However, when testing the semiconductor chip 10, the spring pins 70 generate a circulating current and thus have inductances, thereby deteriorating signal transmission characteristics of the spring pins 70. Also, if lengths of the spring pins 70 lengthen with an increase in a height of the test socket, it is difficult to maintain the shapes of the spring pins 70.
In addition, if compression and extension are repeated in a repetitive test process, a fatigue failure occurs.